PURPOSE: To save the handling time for connecting the telephone calls and to improve the portability of each slave device for a cordless telephone set by providing a function to a master device to select and call only a single slave device of the incoming side through an originating side when a single master device has plural slave devices.

CONSTITUTION: A master device of a cordless telephone set is provided with an incoming data detecting circuit 1 which detects the incoming signal data via a telephone circuit 7 and a circuit input/output circuit 4, a decoding circuit 8 which decodes the incoming data detected by the circuit 1 and then selects and calls one of plural slave devices 10, and a storage circuit 12 which previously stores the ID code corresponding to each device 10. Then a key pad 2 operates the originating data and converts the incoming data into the voice signals via a communication control circuit 3 and a speech circuit 5. Thus the data are communicated between the master device and the devices 10 together with the ID codes via a radio communication circuit 6 and an antenna 9.